tree 3ed58984e5f2e6d3484c33fe7d6355658a6f2f15
parent 5a243e0e97edce27c12f87354fd987526ba1ce95
author NeilBrown <neilb@suse.de> 1172722278 -0800
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1172789616 -0800

[PATCH] md: fix raid10 recovery problem.

There are two errors that can lead to recovery problems with raid10
when used in 'far' more (not the default).

Due to a '>' instead of '>=' the wrong block is located which would result in
garbage being written to some random location, quite possible outside the
range of the device, causing the newly reconstructed device to fail.

The device size calculation had some rounding errors (it didn't round when it
should) and so recovery would go a few blocks too far which would again cause
a write to a random block address and probably a device error.

The code for working with device sizes was fairly confused and spread out, so
this has been tided up a bit.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>